Never ending ? To use atf or gear oil?

ATF or a real, real thin gear oil works. I use ATF myself.

The needle bearings require a thin lube and ATF was the perfect solution for Ford ... it works great.

... The reason anyones T-5 should explode on them is from putting too many ft/lbs into it, not from a choice of poor lubrication.

ATF.

it lives............Oh my gersh it lives..........Die you ferkin thread die!!!!!!!!! 84+ t-5= A.T.F God himself told me that after readin this thread

I beg to differ. My 100% completely stock 1986 5.0 had gear oil in it. I know because I took a bath in it while pulling it out. Let me see if i can get a picture.


Edit: I admit, the fluid may have been changed before I recieved the car. However, I do know that it was filled with gear oil and not ATF when I pulled it out.

i run 50/50 atf and 30w motor oil. thats what jasper recommended???

86 called for Mercon. Aside from the needle bearing problem, the seals in the T5s that call for mercon are designed for Mercon. Running gear oil will prematurely deteriorate those seals.

Couple thoughts. The factory fill can smell like gear oil (it is rancid), but it is not gear oil.

Not all T5's take ATF. Not even all stang T5's take ATF. The early bronco T5's, some camaro T5's, etc (with steel synchros) take gear oil. Early early stang T5's did take gear oil. 89CC in post 19 stated why they require ATF (needle bearings).

When i was going to synthetic, I called Redline and asked if I could use something heavier since I live in the desert. They said they highly advised NOT to. The D4 was formulated just for trannies requiring ATF. Now sure some folks have had luck with other fluids - to each his own. I am just posting my experience.

bit said:

On the other hand it you are like 90% of the people on this board and believe your car can be improved upon from its stock form then find something better. GM synchromesh is a great synthetic lightweight gear oil designed for their modern manuals. As I stated before Redline Shockproof Lightweight gear oil is also a great choose. As the guy above stated a lot of people in here don't know what they are talking about so don't take my word for it.
-Brent

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I don't think GM synchromesh is a synthetic fluid.

IIRC, synchromesh is a blend (and reportedly there are different formulations floating around with different properties. That is one reason for the huge price differences). Lots of scuttlebutt on the internet about it, but I have yet to find definitive info.

Here is Quaker State's product description for its product which meets the same spec as GM's Synchromesh:


PRODUCT DESCRIPTION QUAKER STATE®SYNCHROMESH FLUID is a synchromesh transmission fluid designed for certain manual transaxles and manual transmissions used by General Motors or Chrysler. QUAKER STATE®SYNCHROMESH FLUID is formulated with high quality paraffinic base stocks, a fluidity modifier, multifunctional performance additives, corrosion inhibitors, a foam suppressor and a shear stable viscosity index improver additive. It provides excellent oxidation stability, low temperature performance, excellent synchronizer performance and compatibility with yellow metals, such as bronze, brass and copper components found in manual transaxles and transmissions. This product will satisfactorily lubricate General Motors or Chrysler manual transaxles and transmissions from -40°C to +150°C. APPLICATION QUAKER STATE®SYNCHROMESH FLUID is specifically formulated for synchromesh transmissions used by General Motors requiring General Motors Part No. 12345349 (Specification No. 9985648) Synchromesh Transmission Fluid or Chrysler transmissions requiring Part No. 4874464 (Specification MS-9224). It is also recommended for use in General Motor transmissions requiring General Motors Part No. 12345577. It is listed in the Pennzoil Lubrication Recommendation And Capacities Guideas "GLS." QUAKER STATE®SYNCHROMESH FLUID is NOT intended for all GLS applications. You must verify the manufacturer's part number, indicated by a superscript number and found at the end of the vehicle application listing. BENEFITS Exhibits excellent low temperature performance Meets GM Specification 9985648 Suitable for use in GM manual transaxles and transmissions requiring GM part number 12345349 or 12345577. Meets Chrysler specification MS-9224 Suitable for use in Chrylser transaxles and transmissions requiring part no. 4874464 Excellent synchronizer performance Excellent yellow metal compatibility TYPICAL PHYSICAL AND CHEMICAL PROPERTIES TEST METHOD TYPICAL RESULTS API Gravity ASTM D-1298 27.3 Flash Point, COC, °F ASTM D-92 385 Pour Point, °F ASTM D-97 -50 Viscosity ASTM D-445 @ 40°C, cSt 41.6 @ 100°C, cSt 9.08 @ 100°F, SUS 209.4 @ 210°F, SUS 56.7 Viscosity Index ASTM D-2270 208 Material Number 12/1 Quart 56173 March, 2000 Stock # 59634

Analysis: Note this is a mineral , paraffinic base stock. It has additives and VI improvers, so it is essentially a kind of motor oil adapted for tranny use

EDIT: what does IIRC mean?

About Redline ...

On the Redline website it specifically recommends against using any gear oils (even their shockproof super lightweight stuff) in a transmisison with synchros. That's good enough for me not to want to run it or any other gear oil in a T5 designed for ATF.

(BTW, IIRC = If I Recall Correctly)

89MustangGX said:

About Redline ...

On the Redline website it specifically recommends against using any gear oils (even their shockproof super lightweight stuff) in a transmisison with synchros. That's good enough for me not to want to run it or any other gear oil in a T5 designed for ATF.

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Where did you see that? I could not find that, but I did find this:
About MTL
"Red Line Oil's MTL and MT-90 are designed to provide excellent protection and improved shiftability for manual transmissions and transaxles, having cured the problem of hard shifting in thousands of transmissions with shifting troubles. How? They have the appropriate coefficient of friction for most manual transmission synchronizers (many gear oils, engine oils, and ATFs are too slippery for proper synchro engagement). And, the wide viscosity of MTL and MT-90 allow proper shifting over the entire temperature range which the transmission will experience. The synthetic base oils used have a very high viscosity index which provides relatively constant viscosity as temperature changes. MTL is a low 70W at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise. MT-90 is a thicker 75W90 version of MTL. The shear stability and oxidation stability of these products are excellent, thus the physical characteristics of Red Line MTL and MT-90 will change little with use. This 70W80 GL-4 Gear Oil (SAE 5W30/10W30 engine oil viscosity) is designed for use in manual transmissions and transaxles. Provides excellent protection of gears and synchronizers and its balanced slipperiness provides a perfect coefficient of friction, allowing easier shifting."

Also about Lightweight Shockproof
"A unique lubricant containing a suspension of solid microscopic particles as an extreme pressure agent--unique solid dispersion which cushions gear teeth to help prevent tooth breakage and allows the use of lower viscosities. Recommended for heavily-loaded racing differentials and transmissions, Off Road racing and problem gearboxes. Offers a "best of both worlds" balance of relatively low drag and the utmost in protection. "


I'll keep looking but let me know were they said not to use the above gear oils that they recomend.
-Brent

Bit, what Adam posted is the same thing that Redline's tech line told me (more than once) about using MTL et al, instead of D4 (I was intentionally trying to get the official ok to use a heavier oil).

MTL and MT90 (or often mixes of both) are more often used for trannies requiring GL4 or gear oil.

No one is disputing what works for you. It seems the debate is now simply over what is officially recommended, which is D4.

bit said:

I'll keep looking but let me know were they said not to use the above gear oils that they recomend.

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Here's what it says in the product description for LightWeight ShockProof:

A unique gear oil designed to lubricate racing transmissions and transaxles which see serious loads (not recommended for most syncro-type transmissions).

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Here's what it says in the product description for SuperLight ShockProof:

Used in low-power road racing transxles like Formula Vee and low-power SCCA Production classes (dog-ring type, generally not sycro application where this product can be slippery).

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Here's what it says in the product description for MTL:

This 70W80 GL-4 Gear Oil (SAE 5W30/10W30 engine oil viscosity) is designed for use in manual transmissions and transaxles.

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Here's what it says in the product description for D4 ATF:

Our most popular and versatile ATF, D4 is suitable for use where Dexron III, Dexron II, or Mercon fluids are recommended.

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I think this pretty much answers the question of what is recommended for when your tranny calls for ATF and you go looking for a Red Line product to run in it.

89MustangGX said:

I think this pretty much answers the question of what is recommended for when your tranny calls for ATF and you go looking for a Red Line product to run in it.

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That still says nothing about only running ATF. If you call redline and talk to them about what transmissions are not recommended for shockproof they will tell you it will work in transmissions with "yellow metal" syncros. I guess the bottom line is use lightweight oil, not heavy gear oil. I could personally tell a big difference in the way the trans shifts. Whether or not you choose to use ATF of any kind or something else, it’s your trans and your money spent so do as you wish. Its time for the never ending debate to end. So have fun tearing up the streets/strips with your Mustang and with what ever oil you use.
-Brent

HISSIN50 said:

Bit, what Adam posted is the same thing that Redline's tech line told me (more than once) about using MTL et al, instead of D4 (I was intentionally trying to get the official ok to use a heavier oil).

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I think it's kind of odd that Redline wouldn't give you the go ahead to use MTL since their own documentation states:

Taken from http://redlineoil.com/pdf/6.pdf

"The D4 ATF provides the best low temperature shiftability. MTL provides the better wear protection in most manual transmissions which call for an ATF which can be very important in racing applications. MTL provides the low temperature properties equivalent to a petroleum ATF. All Redline transmission lubricants provide excellent synchronizer compatibility."

I've been running MTL in my T-5 for the better part of its life, which is a good 14 years or more (living in Nevada at the time). I started using MTL before D4 became available and haven't had any reason to change. I do not agree with Redline's statement that MTL has the same low temp properties as a regular ATF. If temperatures drop into the 40° then you begin to have shifting problems though not impossible. You just have to shift slower for a short period of time (the only disadvantage I've seen).

Saleen0679 said:

I think it's kind of odd that Redline wouldn't give you the go ahead to use MTL since their own documentation states:

Taken from http://redlineoil.com/pdf/6.pdf

"The D4 ATF provides the best low temperature shiftability. MTL provides the better wear protection in most manual transmissions which call for an ATF which can be very important in racing applications. MTL provides the low temperature properties equivalent to a petroleum ATF. All Redline transmission lubricants provide excellent synchronizer compatibility."

I've been running MTL in my T-5 for the better part of its life, which is a good 14 years or more (living in Nevada at the time). I started using MTL before D4 became available and haven't had any reason to change. I do not agree with Redline's statement that MTL has the same low temp properties as a regular ATF. If temperatures drop into the 40° then you begin to have shifting problems though not impossible. You just have to shift slower for a short period of time (the only disadvantage I've seen).

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Yeah, I thought it a little funny too. I specifically wanted to use MTL (I am kind of a 'more is better' type of guy. I was concerned that D4 would thin out too much in 110* ambient heat).

You are right - MTL is a bit thicker than D4 (I run a mix of MTL and MT90 in GL4 applications), but MTL is not that thick (neither is MT90, IMHO - atleast when pouring it in 100* ambient temps. LOL).

I am pretty happy with the D4 in hot temps, so I am not sure I would use something thicker (more likely a mix, if compatible). I grew up in cold climates and remember gear-oil trannies being like rowing through molasses when cold.

Oh yeah, I had the impression that MTL was what was recommended before D4 came out. Once that happened, though MTL would work, D4 was more highly recommended.

The issue has to do with the type of synchros in the tranny guys. For many years the T5's have used carbon-fiber lined steel synchros. That's why the DESIGNERS of that tranny specify ATF for a lubricant. Over the longer haul, running a standard or lightweight gear oil is going to cause problems with those type of synchros - incompatibility between the carbon fiber and standard gear/motor oil composition. If you have a tranny with bronze synchros (likely the 'yellow metal' reference mentioned by bit above from Redline's site), then a standard oil-based lubricant will work fine.

But the newer T5's (seems to be confusion on when the synchro switch occurred - 83-84 timeframe) spec ATF fluid because they DON'T have bronze synchros. They have carbon fiber lined steel synchros.

Use what you like -- but be really careful about what you're recommending to those that don't know any better. When the engineers who designed it specify a particular type of fluid, it's generally a good idea to follow their lead.

I run Amsoil synthetic ATF (Mercon/Dexron) in mine.

From an article in FordMuscle's website "Finally you should always run a quality synthetic or synthetic-blend ATF (Mercon-Dextron II / III) in your T5. The fastest way to ruin a T5 is to put in manual gear oil."